WebControl/USB connecting,LEDs light up, but motors not turning

I'm using a Duet Wifi (1.02 or later according to the M122 command. I can't recall which version exactly) running the latest DuetWifi, web server, and web control firmware.

When the board is connected to the main power supply or just USB power, the appropriate LED lights light up. In addition, I can connect to the printer via Pronterface and RepetierHost using the USB, and have no trouble connecting to the board using Web Control. However, whenever I send a movement command to any of the axes or send an extrusion command to either of the extruders, nothing happens. The coordinate value in the control panel changes by the inputted value (i.e. after sending "G1 X1", X0 Y0 Z0 becomes X1 Y0 Z0), but nothing happens to the printer.

The board looks fine, and I've tried using a different stepper motor on each motor port on the board to no avail. When I send a G-code command through Web Control I see no error messages in the "G-code Console" page of Web Control.

I've even tried erasing and re-updating the firmware on the board but this didn't help either.

I've been using the board for over a year, and this problem only came up a couple of days ago, when the printer had worked just fine the day before that. The printer finished the print and after that last print I didn't edit the config.g file or even change anything about the firmware, but the printer wouldn't respond the next day.

I'm thinking it may be a hardware issue, as I've done what I can to deal with firmware issues, and I'm less capable when it comes to dealing with hardware problems. Below is the message I get after sending the M122 command:

@sogus, please send M906 without parameters to verify that the motor currents have been set. Also, after attempting movement, check the Console page of DWC or PanelDue for error messages, and run M122 again to check that the minimum VIN voltage is still good.

The only thing I can think of is that the ENN signal from the microcontroller to the stepper driver chips is stuck at a high level, or that somehow there is no VIN feed to the stepper drivers. But there is probably a much simpler explanation.

You can measure the ENN signal on the expansion connector. It should be +3.3V when no VIN power is present, falling to 0V when VIN power is present and the drivers have been initialized.